Warming at 4 Hiroshima bombs per second: a widget to raise awareness about global warming

A frustratingly stubborn climate myth is that global warming stopped in 1998. It hasn’t. In fact the earth is currently accumulating extra heat at a rate of 4 Hiroshima nuclear bombs per second!

To help drive home the point climate change hasn’t stopped, or paused, but has continued unabated the friendly robots over at Skeptical Science have created this widget showing just how quickly the earth is accumulating energy.


  1. It seems that normal approaches like solid facts and sensible debate aren't sufficient when it comes to getting the message across in the teeth of vested fossil fuel interests.
    What else would afeman recommend be used to galvanise this issue?
    By the way, and I do think this point is recognised, the planet isn't waiting and the status quo is untenable.

  2. I know the backup info on the 4 Hiroshimas is around somewhere and I've seen it, but one rather boggles at the idea; I'm not sure most people will accept it. I'm not interested in communication as Martin Gisser would put it, omphaloskeptically. This needs to reach the mainstream.

    My simplistic metaphor is dealing with obesity. People who promote the "reduction" are missing that this is actually a reduction in the rate of increase.

    People on a diet need first to stop gaining so fast, then to slow down enough to stay level, then to start losing.

    Promotion of the idea that there has been a reduction could be viewed as more of a lie than a direct lie, though that might be sophistry, perhaps even wrong in the same way despite good intentions ...

  3. I am unhappy with this push.

    I dislike the use of big extensive numbers when small intensive ones would do. Also, the nuclear bomb comparison really hides some physical subtleties - although not as much as the hurricane one does.

    Finally, I dislike all the chartjunk.

    The right point is to get people to understand that 1 watt per square meter really is a big deal, not to add up all the energy and swamp them with numbers they can't think about. These numbers are used to numb. We need people engaged, not terrified.

  4. I would argue the units are also of use in terms of making people understand the magnitude of global warming. You tell them it's 0.8°C surface warming, and to any average person that sounds miniscule. Less than a degree? So what? Tell them it's equivalent to 4 Hiroshima bombs or 2 Hurricane Sandys or 4 magnitude 6.0 earthquakes, etc., now they can visualize the magnitude of the human influence on the global climate.

    Further explanations here and here.

  5. I disagree for two reasons.

    1) 4 bomb detonation or 2 Sandys or 4 earthquakes per second isn't some gargantuan number that people can't picture. Nor do I think it will terrify people.

    2) 1 W/m2 or 0.8°C sound small. Deniers exploit this fact all the time. Watts' immediate reaction to the widget was to fall back on 1 W/m2 being a fraction of a lightbulb in a square meter area. Sure it would be great if we could get people to understand this amount of heat is actually a big deal, but I think that's exactly what the widget does. If anyone can find a more effective way to communicate this, I'm all ears.

  6. This is a a very tough problem to visualize in everyday units. It's hard enough to grasp even if you have been studying it for a while. And alarm is an appropriate response once you do grasp it. A pitfall of the Hiro analogy, is that some may well see it as a deliberate attempt to provoke fear by association with the death and destruction associated with atomic weapons, rather than their energy release. (I know the people who did this and that was not their intent.) If people, rightly or wrongly, feel emotionally manipulated, they may well decide to throw the analogy baby out with the climate change bathwater.

    It's not as if others have had better, more effective ideas. But here's my attempt, which, if only by flailing around, shows how hard this is.

    It recently occurred to me that perhaps we could exploit another misunderstanding of orders-of-magnitude of energy flows. Some people have claimed, incorrectly, that global warming could be caused by the extra heat we generate by burning fossil fuels (and uranium, to a lesser extent). It is not unreasonable, especially if you live in a city and you see and feel all the heat coming out of air-conditioner vents, chimneys and exhaust pipes, and then wonder how much that contributes to global warming.

    It turns out that the heat generated by fossil fuels at present is about one-hundredth of the heat coming from radiative imbalance. This means that the Earth is warming up every 15 minutes from GHGs at an amount that is equivalent to all the heat from the fossil fuel we burn in a day. Or, alternatively, that all of the heat energy from all of the fossil fuels burned in history is equivalent to anthropogenic GHG warming over about five months of 2013. Already this year, greenhouse gas warming from the atmosphere has contributed twice as much heat as all of the gas furnaces, vehicles and coal fires in history. (Ballpark numbers only.)

    And that this warming will continue, over centuries, until the Earth and the oceans warm up a few degrees, even if we were to shut down the industrial economy immediately. And that temperature increase would stick around for millennia.

    This kind of stuff--like imagining Y Christmas tree lights burning per X square metres--is fine as a thought experiment and for getting a gut feel for the size of the processes involved. But it is rather ineffective as a communication tool for people who are not disposed to paying attention to this problem in the first place. And it requires a considerable leap of imagination and emotion to go from Christmas lights to an appropriate "Oh, shit!" reaction.

    So, my challenge to the naysayers is to come up with a better analogy.

  7. This isn't a better analogy - it's not even equivalent, but there was one that was bandied around a little bit in the past that equated a the GHG warming from a minute of hair dryer use to a the minute of the ambient heat from a 747 on full throttle. I've not idea how accurate it was, but I thought it was an interesting one, if true.

    It would of course, depend on electricity supply (I guess coal was assumed) and wattage of the hair dryer.

  8. Nice Andy. Ignorant hypothetical don't-know-much-science question: isn't there an important difference with Co2-accumulated heat? The latter moving towards a new input-output equilibrium where the balance is controlled by the atmospheric chemical mix, whereas just dumping heat directly isn't doing that (though if it were a hundred times more than now, one can imagine some territorial/atmospheric side-effects). So the important difference isn't necessarily about heat, it's about permanent lock-in of heat. (Though maybe that's just a difference issue, if we're looking for ways to effectively talk about the amount of energy input).

    Actually, the abstract linked to at the SKS waste heat link does address that a bit - there are effects on annual mean temps and height of planetary boundary layer (for very high watt scenarios).

    Also a bit confused about the basic equivalence of 2.8w m2 vs 0.028 from `anthropenic heat flux' number. Is it just comparing raw watts, as it appears? Shouldn't the comparison be based on total amount of energy input for a given amount of carbon burned? (I'm wondering if it's doing that, but I'm not sure - 2.8w is 3 times the 1 watt figure... confused!)

  9. Dan, that attempt at an analogy was off the top of my head and there may well be unconsidered technical complications with it that don't make it a useful one, apart from whether it is a useful one or not from a communications perspective.

    At the end of The Long Thaw David Archer calculated the GHG warming induced from burning a gallon of gasoline over the atmospheric lifetime of the CO2 ("bad energy") and compared it to the "good energy" we get from burning the gasoline today. the ratio is 40 million to one, bad to good.

    No doubt an economist armed with a calculator and a discount rate assumption would reduce that figure a lot, if he tried to calculate the net present value of that future heat. I wonder if anyone has ever attempted to calculate a discounted Bern parametrization. A project for a rainy day, perhaps.

    In many ways, our brains and methodologies are hard-wired to discount the future and to react slowly--or procrastinate altogether--when we observe slowly developing threats. Maybe we need to be need to be shocked out of that state of natural complacency by vivid imagery, like the 4Hiro counter, when faced by a novel, slow and invisible threat like climate change..

  10. Yes, for the analogy to be apt and useful, it needs to be of something commonly perceived as dangerous, Making the tone trolls uncomfortable is a feature, not a bug.

    Also, I'm reminded to ask again what net present value would be if we manage to drive ourselves extinct. #economicsfail

  11. "Also, I’m reminded to ask again what net present value would be if we manage to drive ourselves extinct. #economicsfail"

    In situations where economic models aren't any use, economic models aren't any use. Same goes for physics models or any model. I don' think many economists think they'd still be in paid employment (or that economics would be any use) if civilisation collapses.

  12. More omphaloskepticism? Glad to see you're still around.

    I continue to think teaching and learning how to acknowledge not knowing rather than papering it over would go a long way to improving public knowledge.

    And as long as I'm here, mizewell use up a few minutes for anyone wanting to take a look. The frenetic accuracy is a treat if you are so disposed:


  13. “Also, I’m reminded to ask again what net present value would be if we manage to drive ourselves extinct. #economicsfail”

    If the extinction comes after the profiteers' death, then the value could get as high as the entire planet's worth.

    Sometimes me cynic thinks that explains it all: “Après moi, le déluge” -- Louis XV.
    Profiteers never cared about local genocide (e.g. the horror of Congo, Heart of Darkness, where ca. 4 got killed for one car rubber tyre). Why should they suddenly care about global genocide?

  14. It would be an embarrassment to actually have this app on your mobile device.

    Here's why. (Pay attention to the last 1.5 minutes.)



  15. Thanks Dan M. Actually, I should have watched the whole thing first. I'm very fond of SciShow Hank Henry's stuff, but this one was too simplistic for this audience. In any case, I was responding partly to Martin Gisser, whose presence I relish, and had been waiting for an opportunity to repeat his wonderful "omphaloskeptic". Be prepared for more offbeat humor from me. I regard laughter as a curative.

  16. I think it's an extremely poor metric. The uninformed will think "Really? Four Hiroshimas per second for how long? And I pretty much see nothing out my window, life goes on as usual. If we were blowing up 240 nukes per minute, 14,400 per hour, 34,560 per day I'm pretty sure I'd notice fairly quickly. These guys are either FOS or liars." We have to give them more credit than this.

  17. Rob, you tell about the ultimate psychopathological form of denial. No metric whatsoever would help those folks, not even destruction and death.

    There are still quite a few lucky ones who by looking out of the window don't have anything to see. Others already had flood waters coming in through the window. Or a forest fire burning down the house. Or a frankenstorm blowing it away. Or drought ruining the farm, or an odd blizzard slowly freezing to death pregnant cattle in summer fur. Or the house sinking in thawing permafrost. Etc. etc.

    It's a bit more difficult for city dwellers to take note, but if the city is on the coast like New York, or at a river like Passau or Leipzig, Germany, or at a mountain like Boulder CO, etc. etc. then the chances are good to see some weird things happening. Not far from my house, there's a medieval house in Passau. They had to add yet another flood mark outside, the highest one ever, above that from 1501.

    Anyhow, for most nowadays the window is a TV or computer screen. And if you really look, you'll see lots of stuff happening somewhere else, sometimes not far away.

    Except you don't want to see.

  18. I think conversation about what we see and what it has or hasn't to do with climate in particular can be and usually is oversimplified.

    I am not convinced that a Hiroshima unit will do anything but exacerbate the panic among the panicking and the dismissal among the the dismissives.

    However, I was of the impression that the numbers were defensible. Stay tuned.

  19. Michael, I appreciate your last two sentences. I wondered and hadn't had time to dive in.

    Martin, regardless, disasters of the nature of tsunamis, devastating hurricanes, dust bowl storms, debilitating droughts have happened throughout history. Again, it's necessary to give people more credit than "four Hiroshimas per second." That is, IMHO, patronizing.

  20. Rob, sorry for harsh and patronizing words. But I'm not sorry for having lost patience with reality deniers. And, science is indeed patronizing.

    As a teen I had the opportunity to study first hand the psychopathology of Auschwitz deniers (some of my grandpa's buddies were low rank SS men). Climate science denial is deja vu all over!
    I have meanwhile given up on the classic middle class retirement dreams. While I still pay into my pension funds (one never knows...) I meanwhile plan for and expect the worst, i.e. a classical Hindu style "retirement" of going into the forest and die there. My major retirement investment is acquiring basic survival, farming and primitive medicine skills. Plus, I'm testing my friends if they are up to the task psychologically: Who can't connect to reality outside ego will not be my friend for long and will be left behind, being a useless burden, to perish in insanity.

    disasters of the nature of tsunamis, devastating hurricanes, dust bowl storms, debilitating droughts have happened throughout history.

    The classic evasion! Did you know that violent death also occurs naturally?

    As I illustrated, who is able to look outside the window (metaphorically) can well sense that climate is meanwhile destabilizing. Test question: How many 500-1000y floods did occur in the year 2013? (Of 2 at least the physical evidence is incontrovertible - no modern meteorological statistics needed: A 500y flood mark in Passau, Germany, and a 1200y old Shiva temple in the Himalayas.)

    But there's also incontrovertible trivial statistical evidence: E.g. http://www.realclimate.org/index.php/archives/2012/08/extreme-metrics/ (straightforward play with Gaussian distribution) or e.g. look at the data of insurance companies http://climatecrocks.com/2013/12/02/no-deniers-in-the-foxholes-insurance-industry-copes-with-climate-reality/ (normalize with geologic catastrophes).

  21. I am not convinced that a Hiroshima unit will do anything but exacerbate the panic among the panicking and the dismissal among the the dismissives.

    Yeah, the panickers are annoying, esp. when they "shoot the messenger" with accusations of alarmism. The dismissives are usually those who are afraid of fear and panic. There is almost no chance to help these poor souls. Hiding the truth is particularly counterproductive, methinks: The longer you keep your head in the sand, the worse your butt will burn one day. Better get used to reality now to minimize trauma. I try to cheer folks up by explaining how privileged we are to live in such interesting and challenging times:

    The history of Life has never been that interesting during the past 65 million years. Quite possibly even the last 300 million years (cf. rapid ocean acidification).

    Oops, another Hiro number...

    I see it that way: Homo S "Sapiens" is in the process of splitting into two species via cultural/emotional evolution. Time to choose sides. No mercy to the ego zombies.

    BTW: New Hansen et al paper out: Assessing “Dangerous Climate Change”: Required Reduction of Carbon Emissions to Protect Young People, Future Generations and Nature. Target is now 1°C...

  22. Martin, you put me in a strange position. I feel we have viewpoints that should not conflict. I don't disagree with you that "things ain't what they used to be." I want to find (well, want someone or someones to find) compelling ways to convince those who watch tv, read, raise their children, work (some for me) 50 hours per week to provide for their families, and are not stupid that bad times will come and that those times will be worse unless jarring changes are made. I want such changes made (though I admit to hypocritical behavior in my house, my car, my airplane, etc.).

    My position is NOT that this heat is not being added to the geophysical system, or that business as usual is no problem, etc. I argue that "four Hiroshimas per second" will have an effect opposite that intended on people who COULD BE CONVINCED of the reality of our predicament. I don't need the four Hiroshimas, and a man or woman who works 10 hours, comes home to dinner, reads for an hour or two or does homework with his or her children, and goes to bed only to repeat the cycle tomorrow (and is generally happy doing so) will not find this compelling. He or she will think, as I stated, that "I'd notice that right away." Passau is not outside his or her window. He or she has read about the dust bowl and the hurricane that struck Galveston in 1900. He or she may remember Hurricane Camille and Hurricane Andrew (obviously, this is US-centric, sorry about that). You can go to Steven Goddard's site to read a constant litany of "the _____ event of 19__ was much worse than the current _______ of 2013. I find such nonsense completely unconvincing but I've looked into it a bit and have a (marginal) background in mathematics and physics. The person I described above has not and does not.

    So please Martin, understand that I'm not carrying the torch for denying the effects of GHG emissions and the bleak future that may await. I have survivalist leanings myself and have made certain accommodations to those leanings. But, in my opinion, the Hiroshima count is ineffective and patronizing to those who are smart, hardworking, but don't read what you read and I read and worry about the unemployment rate or the price of gasoline or the moral decay from which they try to protect their children.

    Finally, citing the positions taken by insurance companies and the military may very well be the proper approach (though people don't trust them either and, in some cases, quite justifiably so).

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